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Camunda 7 Keycloak Identity Provider Plugin including all transitive dependencies
/*
* Copyright 2019 Ben Manes. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.github.benmanes.caffeine.cache;
import static java.util.Objects.requireNonNull;
import java.io.Serializable;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Executor;
import java.util.concurrent.Future;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.checkerframework.checker.index.qual.Positive;
import org.checkerframework.checker.nullness.qual.NonNull;
import org.checkerframework.checker.nullness.qual.Nullable;
/**
* A scheduler that submits a task to an executor after a given delay.
*
* @author [email protected] (Ben Manes)
*/
@FunctionalInterface
public interface Scheduler {
/**
* Returns a future that will submit the task to the given executor after the given delay.
*
* @param executor the executor to run the task
* @param command the runnable task to schedule
* @param delay how long to delay, in units of {@code unit}
* @param unit a {@code TimeUnit} determining how to interpret the {@code delay} parameter
* @return a scheduled future representing pending submission of the task
*/
@NonNull Future schedule(@NonNull Executor executor,
@NonNull Runnable command, @Positive long delay, @NonNull TimeUnit unit);
/**
* Returns a scheduler that always returns a successfully completed future.
*
* @return a scheduler that always returns a successfully completed future
*/
static @NonNull Scheduler disabledScheduler() {
return DisabledScheduler.INSTANCE;
}
/**
* Returns a scheduler that uses the system-wide scheduling thread if available, or else returns
* {@link #disabledScheduler()} if not present. This scheduler is provided in Java 9 or above
* by using {@link CompletableFuture} {@code delayedExecutor}.
*
* @return a scheduler that uses the system-wide scheduling thread if available, or else a
* disabled scheduler
*/
static @NonNull Scheduler systemScheduler() {
return SystemScheduler.isPresent() ? SystemScheduler.INSTANCE : disabledScheduler();
}
/**
* Returns a scheduler that delegates to the a {@link ScheduledExecutorService}.
*
* @param scheduledExecutorService the executor to schedule on
* @return a scheduler that delegates to the a {@link ScheduledExecutorService}
*/
static @NonNull Scheduler forScheduledExecutorService(
@NonNull ScheduledExecutorService scheduledExecutorService) {
return new ExecutorServiceScheduler(scheduledExecutorService);
}
/**
* Returns a scheduler that suppresses and logs any exception thrown by the delegate
* {@code scheduler}.
*
* @param scheduler the scheduler to delegate to
* @return an scheduler that suppresses and logs any exception thrown by the delegate
*/
static @NonNull Scheduler guardedScheduler(@NonNull Scheduler scheduler) {
return (scheduler instanceof GuardedScheduler) ? scheduler : new GuardedScheduler(scheduler);
}
}
enum SystemScheduler implements Scheduler {
INSTANCE;
static final @Nullable Method delayedExecutor = getDelayedExecutorMethod();
@Override
@SuppressWarnings("NullAway")
public Future schedule(Executor executor, Runnable command, long delay, TimeUnit unit) {
requireNonNull(executor);
requireNonNull(command);
requireNonNull(unit);
try {
Executor scheduler = (Executor) delayedExecutor.invoke(
CompletableFuture.class, delay, unit, executor);
return CompletableFuture.runAsync(command, scheduler);
} catch (IllegalAccessException | InvocationTargetException e) {
throw new RuntimeException(e);
}
}
static @Nullable Method getDelayedExecutorMethod() {
try {
return CompletableFuture.class.getMethod(
"delayedExecutor", long.class, TimeUnit.class, Executor.class);
} catch (NoSuchMethodException | SecurityException e) {
return null;
}
}
static boolean isPresent() {
return (delayedExecutor != null);
}
}
final class ExecutorServiceScheduler implements Scheduler, Serializable {
static final Logger logger = Logger.getLogger(ExecutorServiceScheduler.class.getName());
static final long serialVersionUID = 1;
final ScheduledExecutorService scheduledExecutorService;
ExecutorServiceScheduler(ScheduledExecutorService scheduledExecutorService) {
this.scheduledExecutorService = requireNonNull(scheduledExecutorService);
}
@Override
public Future schedule(Executor executor, Runnable command, long delay, TimeUnit unit) {
requireNonNull(executor);
requireNonNull(command);
requireNonNull(unit);
if (scheduledExecutorService.isShutdown()) {
return DisabledFuture.INSTANCE;
}
return scheduledExecutorService.schedule(() -> {
try {
executor.execute(command);
} catch (Throwable t) {
logger.log(Level.WARNING, "Exception thrown when submitting scheduled task", t);
throw t;
}
}, delay, unit);
}
}
final class GuardedScheduler implements Scheduler, Serializable {
static final Logger logger = Logger.getLogger(GuardedScheduler.class.getName());
static final long serialVersionUID = 1;
final Scheduler delegate;
GuardedScheduler(Scheduler delegate) {
this.delegate = requireNonNull(delegate);
}
@Override
public @NonNull Future schedule(@NonNull Executor executor,
@NonNull Runnable command, long delay, @NonNull TimeUnit unit) {
try {
Future future = delegate.schedule(executor, command, delay, unit);
return (future == null) ? DisabledFuture.INSTANCE : future;
} catch (Throwable t) {
logger.log(Level.WARNING, "Exception thrown by scheduler; discarded task", t);
return DisabledFuture.INSTANCE;
}
}
}
enum DisabledScheduler implements Scheduler {
INSTANCE;
@Override
public Future schedule(Executor executor, Runnable command, long delay, TimeUnit unit) {
requireNonNull(executor);
requireNonNull(command);
requireNonNull(unit);
return DisabledFuture.INSTANCE;
}
}
enum DisabledFuture implements Future {
INSTANCE;
@Override public boolean isDone() {
return true;
}
@Override public boolean isCancelled() {
return false;
}
@Override public boolean cancel(boolean mayInterruptIfRunning) {
return false;
}
@Override public Void get() throws InterruptedException, ExecutionException {
return null;
}
@Override public Void get(long timeout, TimeUnit unit)
throws InterruptedException, ExecutionException, TimeoutException {
requireNonNull(unit);
return null;
}
}